Why is my render so fuzzy?
You have the focus of the camera set a value that is not the distance from the camera to your object,  and are using a very wide lens aperture. Your scene is "out of focus".

Change the value for distance to the actual distance form the camera to your object, and maybe try a higher number for the f-stop.

To find where your camera is focusing you can enable display->Limits. If you move the focus you'll see a cross mark that indicates where the focus point is:



in 2.8 enable Limits in the Viewport Dislpay section of the camera, enable Depth of Field and set the distance to your object.



A trick you can do is use an empty. Move the empty to the place you want the camera to focus on and select the empty (or any other object as the focus target).



For more info read the blender manual's page for Depth of Field